Solid shaped sterilizing, sanitizing, and disinfecting compositions



United States Patent 3,296,069 SOLID SHAPED STERILIZING, SANITIZING, ANDDISINFECTING COMPOSITIONS Xavier Kowalski, St. Louis, Mo., assignor toMonsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing.Filed Aug. 20, 1965, Ser. No. 481,422 16 Claims. (Cl. 16733)' Thepresent invention relates to novel, sterilizing, sanitizing, and/ ordisinfecting compositions and to processes for preparing saidcompositions. The present inventiOn further relates to stablecompositions, in dosage unit form, containing a chlorine liberatingcompound, from which active and/or available chlorine may becontrollably released over prolonged periods of time. The presentinvention more particularly relates to stable, novel, sterilizing and/or disinfecting shapes or sticks containing an N-halogen organicheterocyclic compound and which are usable and eflicient in maintaininga substantially constant effective level of active chlorine under useconditions, e.g. in swimming pool water and other aqueous media, forprolonged periods of time. The present invention also relates to novelprocesses for preparing such stable compositions in the form of varioussolid shapes or configurations, including sticks and the like. Theexpression or term stick or sticks as used herein refers to a solidcylindrical shaped or tubular article which is composed of variouspercentages of compounds which have been mixed together to form thenovel composition of the present invention and subsequently compressedtogether to form such sticks. The preferred sticks of the presentinvention are solid cylinders similar in size to the commerciallyavailable, underarm deodorant sticks,

The term dosage unit form as used herein is intended to mean and torefer to solid, physically stable, compact, fabricated compositions indistinct units, which units will not instantaneously disintegrate (butrather require some period of time, for example, 5 hours to 2 daysdepending upon the size of the stick, to erode or dissolve) whenimmersed in and/or contacted with water or other aqueous media. The termdosage unit form, as used herein, is also intended to mean a solid,compressed composition fabricated without adhesive additives or bindersand compacted or compressed under a pressure whereby the density of thedosage unit form comprising various ingredients therein is at least 25%more than the density of such ingredients in the uncompressed or bulkstate.

The novel sterilizing and/or disinfecting compositions in unit dosageform or stick form may be used in any apparatus or device which promotesslow and uniform erosion of such form when subjected to the erosive ordisintegrating action of water or other aqueous media to provide auniform supply of active and/or available chlorine in such water oraqueous media. While the stick shape or form (as above defined) .is thepreferred dosage unit form of the invention, compositions in otherconfigurations or shapes may also be used in aqueous media for supplyingactive and/ or available chlorine thereto. Other such configurations mayinclude granules, tablets, pills, pellets, briquettes, and the like. Thevarious aforementioned configurations, including the stick shape, maycontain varying but predetermined amounts of a solid compound capable ofreleasing available chlorine when contacted with water such as achlorinated triazine compound of the compositions hereinafter described.Such dosage unit form generally contains predetermined amounts ofavailable chlorine, usually provided by a chlorinated cyanuric acidcompound and may vary widely in size and/ or configuration dependingupon the use of the particular composition.

The present invention, however, is more particularly Patented Jan. 3,1967 directed to sterilizing and disinfecting sticks which are pools andcan easily be incorporated in the water circulation system thereof toerode and release active and/ or available chlorine in the circulatingwater in uniform and readily controlled quantities. The novelcompositions of this invention, in dosage unit form, are surprisinglychemically stable to loss of available chlorine for long periods of timewhen stored in an air atmosphere characterized by high temperatures(e.g., 120 F.) and high humidity (e.g., 50-95%).

Compositions of matter containing certain chlorinated cyanuric acidcompounds have previously been described as bleaching, sterilizing anddisinfecting agents, Such compositions contain compounds such astrichlorocyanuric acid (US. 3,002,931), dichlorocyanuric acid or thesodium salt of dichlorocyanuric acid (US. 2,913,460); or N-chlorinatedhydantoins such as 1,3-dichloro-5,5-dimethylhydantoin; or chlorinatedmelamine. Of the above-mentioned compounds, trichlorocyanuric acid anddichlorocyanuric acid have more recently been employed commercially inbleaching, sterilizing and disinfecting compositions. Theselast-mentioned compounds have usually been marketed as dry powders perse or have been suggested for use in substantially dry, formulatedcompositions in combination with other compounds such as certain anionicsulfates or sulfonates, as for example, sodium salts of long chain alkylsulfates, sodium salts of alkyl naphthalene sulfonic acids, sodium saltsof alkyl benzene sulfonic acids and the like. Compositions such as thosedescribed in the aforementioned patents preferably also contain one ormore detergent builder salts including alkaline, Water-soluble, alkalimetal salts such as trialkali metal phosphates, di-alkali metal hydrogenphosphates, alkali metal pyro, ortho, and metaphosphates, and inertdiluents, which may also have detergent building properties, such as forexample, neutral, inert, alkali metal sulfates and chlorides. Such drypowdered compositions have certain'limitations in that, in mostinstances, they have to be accurately measured before being added toaqueous media in bleaching, sterilizing, or disinfecting procedures suchas, for example, the wash liquor in a dishwashing or launderingoperation, the water in a swimming pool or in a lavatory sanitizingoperation. Also, particularly in the latter two instances, an excessiveamount of chlorine-containing material must be added initially in orderto maintain an effective active chlorine level for even a short periodof time. The reason for this is that active chlorine content of suchpowdered compositions is dissipated rapidly in dilute aqueous solutionsand the desired bleaching, sterilizing or disinfecting activity,especially the bactericidal and/or algicidal activity required forswimming pool operations, is lost in a short period of time.

It has been proposed heretofore in Example IV of U5. Patent 2,067,738and Re. 24,412, both issued to Edgar E. Hardy, that 9.52 parts oftrichlorocyanuric acid, 41.98 parts of trisodium phosphate and 2.5 partsof starch or other suitbale binder may be uniformly blended together toform a dry stable mixture which can be subsequently pressed into cubessuitable for use as household bleach. Hardy further notes that certainalkaline salts are suitable -for use in his compositions includingalkaline salts such as sodium carbonate, borate, silicate, or phosphate.Although the cubes or tablets disclosed in these Hardy patents overcomesome of the disadvantages inherent in the use of powders, such cubes ortablets contain substantial quantities of starch which after a period oftime tend to react with and/or decompose trichlorocyanuric acid. Suchcompositions tend to lose available chlorine after they have been storedfor some time, and particularly in the presence of small amounts ofmoisture.

Thus, it has been found that when such cubes or tablets contain evensmall amounts of moisture, whether by accidental contamination, orotherwise, or by the addition to water, the trichlorocyanuric acid tendsto decompose and the compositions tend to lose available chlorine at arelatively rapid rate. This means that the moisture contaminated cubesor tablets contain less available chlorine than would be expected on thebasis ofthe trichlorocyanuric acid initially present therein andconsequently, under such circumstances, the cubes or tablets are usuallydeficient in available chlorine for the general purpose for which theywere initially formulated. Contamination of the cubes or tablets withmoisture may also occur by mixing the ingredients in the presence ofmoisture without taking precaution to keep the ingredients in a drystate or by storing the cubes or tablets in open containers or incontainers which are not sufficiently tight to exclude moisture.

Loss of available chlorine is also experienced when such cubes ortablets are added to water, in which they rapidly dissolve or disperseto form aqueous solutions and/or suspensions, when such aqueoussolutionsor suspensions are left to stand or are permitted to stand forsome period of time before and during use. Thus, in an application, suchas the use of such cubes or tablets in disinfecting water in swimmingpools, excessive amounts of such cubes or tablets must be added to theswimming pool water if an effective level of available chlorine is to bemaintained for a practical period of time. Also, as noted above, thecubes or tablets may become contaminated with moisture prior to use invarious ways with the resulting loss in available chlorine. in additionto the Hardy patent, Reissue 24,412 another patent which may be somewhatrelated to the subject matter of the present application is CanadianPatent 607,974.

Any particular problems associated with the utilization of compositionsin dosage unit form, specifically as sticks, in swimming pool water as adisinfectant, sanitizing and/or sterilizing composition is usuallyassociated with the effect which water will have on such dosage unit foror on the sticks per se, specifically, the sticks will tend to crack andswell easily due to the high rate of solubility of the stick in water orhigh erosion rate therein which will then result in an erratic chlorinesup ply to the swimming pool water.

In the past, disinfectant compositions (in powder, granular, tablet,pellet, etc. forms) were highly unsatisfactory in supplying availablechlorine atoms to swimming pool water or other aqueous media because ofthe dissolution, erosion, etc. rates thereby resulting in an erraticsupply of chlorine thereto. Specifically and stated in other words, if,for example, a composition in powdered, granular or tablet form wasadded to swimming pool water, the amount would be added all at one timeand the swimming pool water would be slugged with a very concentratedsolution of available chlorine. The present invention yields a highlysatisfactory disinfectant stick which has unique solubility, dissolutionand erosion rates in aqueous media whereby there is supplied to suchmedia a constant and/or controllable amount of available chlorine at apredetermined rate, as in the water of a swimming pool.

It is thus seen from the aforementioned discussion and/ or descriptionthat there is a definite need for unit dosage forms or sticks of thetype described herein which do not exhibit undue loss of availablechlorine during storage under normally prevailing conditions and which,when placed in a suitable apparatus or device in which such forms orsticks can be eroded by the action of water, Will controll-ably releaseavailable chlorine and will maintain a substantially constant level ofavailable chlorine in 4 such Water or other aqueuos media (as in aswimming pool) for prolonged periods of time.

While it is known in the art that dichloroisocyanuric acid per se,trichl-orois-ocyanuric acid per se and an alkali or alkaline earth metalhypochlorite per se {particularly calcium hypochlorite) are chemicalcompounds which may be used to supply available chlorine to an aqueousmedia such as swimming pool water, calcium hypochlorite per se forms avery poor unit dosage form or stick in that both its manufacturingcharacteristics, i.e. ability to form and hold a stick shape, are poorand its erosion rates are too high for practical commercial purposes.Furthermore, swelling and crumbling of said hypochlorite stick incontact with water occurs readily. On the other hand,trichl-oroisocyanuric acid per se may be formed into a stick, but theproperties or characteristics of such a stick, i.e. its ability to formand hold a stick shape, are poor and, therefore, such stick is notsatisfactory for practical commercial purposes, specifically where aconstant and controllable rate of available chlorine is required to befed to an aqueous media. It might further be added that thetri-chloroisocyanuric acid stick presents a greater hazard in that ithas a a higher chlorine content and with its less stable character, thanthat of dichloroisocyanuric acid, a health problem is presented; i.e.,there exists the possibility of evolving large quantities of chlorine ina small area wherein a person may come in contact therewith. By the sametoken, dichloroisocya-nuric acid per so may be formed into a stick whichhas desirable erosion rates but such stick has a tendency to swellconsiderably and crack when in contact with water. Therefore, such stickhas not been found to be practical for commercial purposes. This latte-rchlorinated triazine compound, i.e. dichloroisocyanuric acid, appearsmost promising but no one in the art has presented a solution to theswelling and cracking problem which the present applicant was confrontedwith and has successfully overcome with the present invention.

From the following description and Tables I-IV herein, it will be seenthat the aforementioned problems have been overcome by the presentapplicants inventive contribution to the art. Consequently, thisinvention provides a dosage unit form of dichloroisocyanuric acid whichwill have desirable erosion, dissolution, and/ or solubility ratessuitable for supplying available chlorine to swimming pool water inproportions which are well within the standards recommended by variousstate and federal public health departments.

Thus, it will be shown from the description and data hereinafter setforth that the novel stick will yield a configuration and compositionwhich is highly satisfactory for the particular end use of supplyingavailable chlorine, at a continuous and controllable rate, to a largebody of water such as that in a swimming pool or commercial coolingtowers. The novelty, unobviousness and uniqueness of the presentinvention are then readily seen from the data and discussion hereinafterset forth.

It is accordingly one object of the present invention to providesterilizing, sanitizing, and/or disinfecting compositions, in dosageunit form, comprising chlorine containing compounds from which availablechlorine can be released in aqueous media over a predetermined period oftime or over prolonged periods of time, if desired, and which exhibitimproved stability toward loss of available chlorine during storage inthe presence of moisture.

It is a further object of this invention to provide novel, stablecompositions, in dosage unit form, containing chlorinated cyanuric acidcompounds and which are efiicient in maintaining, in aqueous media suchas swimming pool water, constant and controlled levels of activechlorine for sterilizing and/or disinfecting operations overpredetermined periods of time or over prolonged periods of time, ifdesired.

It is still another object of the present invention to provide novelprocesses for preparing the composition referred to in the precedingobjects.

Still further objects and advantages of the present invention will beapparent from the following description and the appended claims.

The present invention, in general, provides a composition, in dosageunit form, comprising mixtures of (a) a non-deliquescent, solid,chlorine-containing compound selected from the group consisting ofdichloroisocyanuric acid, [(monotrichloro) tetra-(monopotassium-dichloro) pentaisocyanurate, and (monotrichloro)(monopotassium dichloro)diisocyanurate; (b) a metal salt of an aliphaticcarboxylic acid having at least carbon atoms; and (c) a granular,anhydrous metallic salt selected from the group consisting of anhydrousinorganic zinc and copper salts and anhydrous organic zinc and coppersalts, which last-mentioned metallic salt is further characterized inhaving a solubility of at least 10 grams per 100 milliliters of water ata water temperature of 20 C.

More specifically, in a preferred embodiment, the present inventionprovides compositions, in dosage unit form, comprising mixtures ofdichloroisocyanuric acid; the aforementioned granular, anhydrous copperor zinc inorganic or organic salts; and from about 0.5% to about 2.0% byweight based on the weight of the composition of a metal salt of analiphatic carboxylic acid, preferably an alkyl carboxylic acid or fattyacid having at least 10 carbon atoms in the aliphatic or alkyl groups.

The compositions of this invention are otherwise substantially free fromother organic materials and have excellent storage stability in thepresence of air and will controllably release available chlorine, inaqueous media such as cooling tower water and swimming pool water, insterilizing, sanitizing and/ or disinfecting operations over apredetermined period of time or over prolonged periods of time ifdesired.

Dichloroisocyanuric acid is the preferred chlorinecontaining compoundutilized in the present invention because of its desirable erosion ratesand stability, as compared, for example, to trichloroisocyanuric acid.However, other chlorinated triazine compounds such as those described inUS. Patent 3,150,132, i.e. [(monotrichloro)tetra (monopotassiumdichloro)]pentaisocyanur-- ate. (monotrichloro)(monopotassium dichloro)diisocyanurate and mixtures thereof, may be used in place of or incombination with the dichloroisocyanuric acid. In order to avoid theenlargement of the present specification, US. Patent 3,150,132 isincorporated herein by reference.

The dichlorocyanuric acid employed in the compositions of this inventionhas been described in the literature and has been referred to aspossibly existing in the keto and enol forms. In any event, the compoundhas a theoretical available chlorine content of 71.1%. The commerciallyavailable product containing between about 68 and 72% available chlorinecan also be used. The term available chlorine as employed herein is usedin its usual technical meaning as employed in the sodium hypochloriteart. The available chlorine in a given compound is determined byanalyzing for the amount of chlorine that can be liberated from thecompound by treatment with an aqueous acid solution. Dichloroisocyanuricacid and dichlorocyanuric acid are used interchangeably throughout thepresent application and are deemed equivalent for the purposes of thisinvention.

Metal salts of aliphatic carboxylic acids which have at least 10 carbonatoms, preferably between 10 and 30 carbon atoms, in the aliphatic oralkyl group which are suitable for inclusion in the compositions of thisinvention include fatty acids such as unsaturated monoand dicarboxylicacids, and hydroxy carboxylic acids which are saturated and unsaturatedand have at least 10 carbon atoms in the aliphatic or alkyl group.EXamples of metal salts of unsaturated monocarboxylic acids which may beemployed include, for example, salts of hypogeic, oleic, elaidic,erucic, behenic, linoleic and linolenic, brassidic acids and unsaturatedhydroxy carboxylic acids such as ricinoleic acid; examples of metalsalts of unsaturated dicarboxylic acids include metal salts of2-dodecenedioic acid, tridecenedioic acid and the like; examples ofsalts of alkyl (saturated) monocarboxylic acids include salts ofundecylic, lauric, myristic, palmitic, margario, stearic acids; examplesof salts of alkyl dicarboxylic acids include salts of decanedioic,undecanedioic, tridecanedioic, pentadecanedioic acids. Metal salts ofsaturated monocarboxylic acids having from 10 to 18 carbon atoms areparticularly preferred.

Suitable metal salts of the above-described carboxylic acids includealkali metal salts such as sodium, potassium and lithium salts; alkalineearth metal salts such as calcium and barium salts; and zinc andmagnesium salts. For example, alkali metal oleates, palmitates,stearates and the like as well as the corresponding alkaline earth saltsand the zinc and magnesium salts are particularly suitable; alkalinealkali (calcium and sodium) stearates being the most preferred. Actuallyfor swimming pool use, sodium stearate is preferred over the calciumsalt since it is more soluble in water in the low concentrations inwhich it is used in the composition of this invention.

It has presently been found that granular, anhydrous copper and zincsalts, both organic and inorganic, when combined with the aforementionedchlorine-containing compound such as dichloroisocyanuric acid and ametal salt of an aliphatic carboxylic acid produce, after formulation, aunique unit dosage form or stick which is free from the aforementionedundesirable swelling and/or cracking characteristics which are presentin the aforementioned prior art compositions containingdichloroisocyanuric acid. Specifically, these zinc and copper salts mustbe utilized in the anhydrous form in order that the overall formulationbe stable which would not be the case if said salts were in the hydrateform which would consequently cause a loss or reduction of availablechlorine in the novel composition. Secondly, the cop-per and zinc saltsshould have a solubility of at least 10 grams per milliliters of waterwhich is at a temperature of 20 C. One of the surprising aspects of thepresent invention relates to the fact that the copper or zinc saltshould have a high solubility (greater than 10 grams per 100 millilitersof water) whereas the major ingredient, e.-g. dichloroisocyanuric acid,in the novel compositions has a relatively low solubility, 065 gram per100 milliliters of water which is at a temperature of 20 C.

As examples of anhydrous inorganic and organic copper salts which fallwithin the aforementioned limitation, there may be mentionedcopper-chloride, chlorate, bromate, bromide, dichromate, -fluosilicate,lactate, nitrate, salicylate, seilenate, sulfate, metaborate, andphenolsulfonate. It is to be noted that the aforementioned coppercompounds are in the cupric form. Generally, most of the copper salts inthe cuprous form do not have the high solubility characteristic which isrequired of said salts before it can be utilized in the novelcompositions of the present invention, but euprous salts are notexcluded if they have the proper solubility characteristics hereinbeforespecified. However, the aforementioned copper salts are merely exemplaryand are not limitative and other copper organic and inorganic saltshaving the specified characteristics may be utilized in the compositionsof the present invention.

Examples of inorganic and organic zinc salts, which may be used in thecompositions of this invention, include zinc-chlorate, chloride,sulfate, bromate, bromide, iodide, permanganate, acetate, -biutyrate,dichro-mate, sfluosilicate, nitrate, 2-phenol-4-sulfonate,hypophosphite, and picrate. It is preferred, of the aforementionedcopper and zinc salts, to use copper and/ or Zinc salts of inorganicacids having the requisite solubility, etc. characteristics.

Another limitation directed to the copper and zinc salts is that theyshould be compatible with the chlorinecontaininig compound. The termcompatibility as used herein generally refers to the fact that the saidcopper or zinc salt has no adverse effect on the erosion rates,stability, etc. of the unit dosage form or stick. More specifically,there must be no significant chemical interaction and/ or reactionbetween these salts and the chlorinecontaining compound which wouldadversely affect a significant reduction in the amount of availablechlorine released into an aqueous media at a controllable rate. It ispreferred to use a salt such as copper sulfate, copper chloride, zincsulfate, zinc chloride, or zinc acetate in the novel compositions of thepresent invention. It is also within the scope of the present inventionto employ mixtures of the various copper and zinc salts.

As described in the preceding paragraph, copper sulfate, copperchloride, zinc sulfate, zinc chloride or zinc acetate are the mostdesirable compounds. Utilization of these materials in the compositionsof the present invention yields a stick formulation which is highlysatisfactory for the particular end use and is particularly suitable foruse in swimming pool applications. Specifically, these materials whenused in conjunction with dichloroisocyanuric acid produce a compositionwhich has the desirable characteristics, i.e. solubility rate,stability, nonswelling, non-cracking, etc., to effectively releasechlorine to an aqueous media. It is to be noted that adic'hloroisocyanuric acid stick per se or one containing smallquantities of the hereinbefore defined metal salts of a car-boxylicacid, when contacted with water, results in excessive swelling andcracking which is a highly undesirable characteristic because swellingcauses relatively rapid disintegration of the stick.

As also mentioned heretofore, a trichloroisocyanuric acid stick per se,when contacted with water, produces an offensive odor, and thesolubility rate of such stick is very low. It was unexpectedlydiscovered in the present invention that the use of copper and/ or zincsalts with dichloroisocyanuric acid produces a high quality stick whichcould be effectively eroded (-by impinging jets of water on one endthereof while said stick was in a vertical position) to yield acontinuous and controllable rate of available chlorine and subsequentlysupplying such chlorine to an aqueous media. -On the other hand, theutilization of copper and/or zinc salts with trichloroisocyanuric acidproduced a unit dosage form, after formulation, which still has moderateto severe cracking and swelling characteristics. (Itis to be noted thatboth the dichloro and trichloro stick referred to in the precedingsentence also contain a metallic salt of a carboxylic acid ashereinbe'fore defined.)

It is believed that the copper and/or zinc salts, due to their inherenthigh solubilities, produce minute channels in the stick whereby anynitrogen trichloride gas, which may be produced due to the breakdown ofthe triazine ring when using dichloroisocyanuric acid, escapes from thestick before sufficient gas pressure builds up to cause stick crackingand/ or splitting. Furthermore, it is also believed that since thecopper and zinc salts are utilized in the anhydrous form, the overallstick hydration rate is somewhat decreased, i.e. the chlorine-containingcompound has a reduced hydration rate because the anhydrous copper and/or zin salts readily absorb the Water. Consequently, it is believedthere is a reduction of heat generated due to hydration which heatnormally causes the liberation of nitrogen trichl-oride gas due to thebreaking of such triazine ring. The aforementioned theories are merelyideas as to what purpose and/or end result is obtained when the copperand/or zinc metallic salts are used. What may happen and the exactchemistry is not known and the applicant does not wish to be limited toany theory or ideas presented herein in conjunction with his novel stickcomposition.

In another preferred embodiment of the invention, the

compositions, in dosage unit form, comprise, on a solid basis, (a) atleast preferably from about to 98% by Weight of dichloroisocyanuricacid, (b) from about 0.25% to about 5 preferably from about 0.5% toabout 2.0% by weight of anhydrous, granular copper or zinc inorganicsalts, preferably copper sulfate, copper chloride, zinc chloride or Zincsulfate, and (c) from about .25 to about 2.0%, preferably from about .5to about 1.5% by weight of sodium or calcium stearate.

In another preferred embodiment of the invention, the compositions indosage unit form, comprise, on a solid basis, (a) at least 90%,preferably from about 95 to 98% by weight of dichloroisocyanuric acid(b) from about 0.5 to 2.0% by weight of anhydrous, granular copper orzinc organic salts, preferably copper lactate, copper salicylate, zincacetate or zinc 1-phenol-4-sulfonate, and (c) from 0.25 to about 2.0%,preferably from about .5 to about 1.5% by weight of calcium or sodiumstearate. As previously set forth in the objects of this invention, suchnovel compositions are useful in swimming pool water, as disinfectionand sanitation agents.

While the range of from about 0.25% to about 5% copper or zinc salts hasbeen hereinbefore indicated to be useful, larger amounts, e.g. 10% byweight based on the total weight of the composition, may be utilized andare within the scope of the present invention. It should be pointed out,however, with reference to the use of copper sulfate, that this salt(when incorporated in the stick which is thereafter contacted withwater) may yield some discoloration, i.e. bluish tint, in the aqueousmedia at higher levels than 5% by weight based on the total weight ofthe composition, which color may be deemed objectionable from only anesthetic point of View.

The size of the particles of the various ingredients used to make orprepare the novel compositions of the present invention are deemedcritical and have a significant effect on the dosage unit form or stickper se, specifically the erosion and/or dissolution rate. Thechlorine-containing compound such as dichloroisocyanuric acid and thecopper or zinc salt compound such as copper chloride or zinc acetateused should be the granular form, that is, the particles thereof shouldpass through a No. 10 mesh US. Standard screen and preferablysubstantially all (at least 90%) of the particles should be retained ona No. 100 mesh US. Standard screen. Stated differently, the size of theparticles are preferably such that more than 90% of the particles orcrystals will pass through a sieve or screen opening having an area of2.0 square milimeters and will not pass through or be retained on asieve or screen having 0.18 square millimeter opening. Thebefore-mentioned particle sizes usually connotate a granular materialand is the preferred embodiment of the present invention, however, extragranular or larger particles of material may be acceptable, can be used,and are within the scope of the present invention. Furthermore, smallerparticles, i.e. particles passing through a No. 100 mesh, can beutilized; however, these may possibly change the stick properties whichare important in the use of said stick for commercial applications.

As stated above, the main ingredients in the stick formulations orcompositions are granular, whereas the particle size of the particles ofthe metal salt of the aliphatic carboxylic acid, e.g. sodium or calciumstearate, is usually in the range of between 1 to 100 microns and preferably between 1 and 50 microns, i.e. powdered material, and usuallyadheres to and coats the larger particles of the main ingredients whenmixed therewith. These powdered metal salts not only act as a lubricantfor the stick while it is being compressed but such salts also have avery critical effect on the erosion and/or dissolution rates of thestick when such sticks are contacted with an aqueous media such aswater.

It is not readily understood by what mechanical or chemical means themetal salts of the aliphati carboxylic acid contribute to the good stickformulation and desirable characteristics thereof. One theory, inconjunction with the erosion data obtained when using such metal salt,is that there may be an interaction between the main ingredients and themetal salts to yield the favorable end results. The aforementionedtheories are merely ideas as to what may happen and the exact chemistryis not known and the applicant does not wish to be limited to any theoryor ideas presented herein in conjunction with his novel stickcomposition.

The stick or dosage unit form of the present invention may weigh from 50to 1,000 grams or more and preferably from 100 to 500 grams dependingupon its size and end intended use, and may contain from 60% to as muchas 80% available chlorine depending upon the particularnon-delinquescent, solid, chlorine-containing compound used. Thepreferable size of the sticks to be used to supply chlorine ranges fromabout inch to approximately 1 /2 inches in diameter and from about 4inches to about 6 inches in height or length and weigh from about 200 toabout 250 grams. The stick density ranges from approximately 90 to about110 pounds per cubic foot; the average density of the sticks is about100 pounds per cubic foot. The stick can be formulated so as to erode,dissolve, or disperse in an aqueous media such as swimming pool waterover a period of from approximately 1 hour up to about 64 hours orlonger depending upon factors such as (1) the size of the sticks, (2)the volume of the water being treated, and (3) the rate at which suchmedia is permitted to erode or dissolve the unit dosage form.

The general process for preparing the dosage unit form or sticksembodies the steps of mixing the ingredients together to form a uniformmixture and compressing the mixture under pressure to form a dosage unitform of solid stick, preferably the compressing step is carried outuntil the dosage unit form or stick has the dimensions and densitieshereinbefore described.

The mixing (preferably by mechanical means) of the various ingredients,prior to compression into dosage unit form, may be accomplished in anumber of ways commonly employed in mixing dry or substantially drymaterials such as for example, by stirring, tumbling, and the like. Itis important, however, that the mixing be carried out in such a mannerthat the particle size of the particles of the various ingredients isnot appreciably altered in mixing the dry materials; tumbling isparticularly preferred. By this aforementioned intimate mixing step, adry, flowable, and uniform mixture or composition is formed which, afterbeing compressed into a dosage unit form such as a stick, will notexhibit in said stick any separate layers or strata of individualingredients. The mixtures or compositions, prepared as described above,may be then converted or compressed into a variety of configurations toprovide the dosage unit form of the present invention. The configurationwhich is preferable is a stick such as a solid right cylinder whichwill, in most instances, provide a dosage unit form of suflicientmechanical strength to substantially minimize or prevent fracture undershipping, han dling, and storage conditions. In addition, such sticks,when contacted with water under conditions conducive to erosion, willusually erode uniformly and supply a continuous and constant rate ofavailable chlorine to swimming pool water. The preferred dosage unitform or stick in the configuration of a right cylinder may have anydiameter and/ or length desired, but preferably has the dimensionshereinbefore described, and such forms or sticks may be obtained orshaped by employing a variety of apparatuses or presses such as, forexample, a Colton press or a Carver press.

A wide range of pressures may be used to form the sticks of thisinvention and the dispersion time of the finished product is onlypartially effected by the compression pressure and compression timeemployed. Thus, for example, a predetermined amount of the uniformmixture of ingredients is injected into the die of the press, compressedat a pressure of from 11,000 to about 12,000 p.s.i. for a period rangingfrom 1 second up to 30 minutes and even greater and removed from saiddie. It has been ascertained that with a pressure of about 3,000 to18,000 p.s.i. satisfactory forms or sticks can be obtained. On the otherhand, at pressures of approximately 2,000 p.s.i., the sticks usuallywill fall apart and at a pressure of as high as 20,000 p.s.i., thesticks will exhibit a very low solubility and/or erosion rate whensubjected to contact with an aqueous media.

In conjunction with the over-all process for manufacturing the sticks ofthe present invention and, more specifically, the items set forth underthe heading Stick Manufacture which are found in the subsequent tables,the formation of the stick and its compacting aspects refer mainly tothe physical characteristics and appearance and these to some extent aredependent on the amount of salt of carboxylic acid (e.g. stearate) usedwhich is believed to act as a lubricant. The mold release data referredto in the tables indicate generally the ease with which the stick couldbe pushed out from the die which in turn is dependent upon the amount ofthe lubricant used. The item designated capping in the tables generallyrefers to the small lumps, if any, of material sticking to the diesurface. Rusting of the dies was not experienced in the production ofthe sticks due to the fact that water was not used in the compositionsor formulations, except No. 3. However, minor amounts, e.g. less than2%, of water can be used, if desired, and if die rusting is not criticalor severe. It was also ascertained during the stick manufacturing thatit was important to have a uniform distribution of the salt of thecarboxylic acid, such as stearate, throughout the mixture or compositionbecause it is believed to affect the ability of the stick to be releasedfrom the compacting surface. The lack of uniformity in particle sizedistribution of the ingredients in the mixtures is apt to causevariation in stick length, stick strength, and corrosion rates. The termstick strength generally refers to the length of stick which can behandled Without severe breaking problems.

In accordance with the processes of the present invention, it has beenfound possible to compress the hereinbefore described mixtures employedin this invention into dosage unit forms, preferably sticks, byprocesses which eliminate the use of organic adhesives or binders of theprior art and which also eliminate or substantially eliminate thenecessity of agglomerate formation required by the prior art processes.

A further understanding of this invention will be obtained from thefollowing specific examples which are intended to illustrate theinvention but not to limit the scope thereof, parts and percentagesbeing by weight unless otherwise indicated.

EXAMPLE I Dry, mixed compositions, containing the ingredients set forthin Table I, were prepared by mixing said ingredients in a one-halfgallon jar and rotating or agitating said jar for approximately 1 to 4minutes in order to insure thorough mixing and to prevent anysegregation of the individual ingredients. The various ingredients andtheir specifications are set forth immediately below and were typical ofthe materials used in preparing the novel compositions.

Dz'chlorocyanuric acid Characteristics: Limits, percent Availablechlorine min 66 Moisture max 0.2 Screen analysis (cumulative values) On30 mesh max 2.0 On 60 mesh min On 100 mesh min mesh max 10 Anhydrouscopper sulfate Characteristics: Limits, per-cent Moisture max 0.5 Screenanalysis (cumulative values)- On 20 mesh max 1 On 30 mesh max 20 On 100mesh min 90 100 mesh max Sodium steal-ate Characteristics: Limits,percent Screen analysis- On 140 mesh 1.2 On 170 mesh 2.6 On 230 mesh 6.0On 270 mesh 44.0 -270 mesh 47.0

-.Norn.Tl1e above screen sizes refer to US. Standard mesh screens.

The dried and mixed ingredients in the form of a uniform mixture werethen compressed by a Carver press for approximately 25 minutes or untilthe maximum pressure of approximately 12,000 p.s.i. was reached. Apredetermined amount of the composition was used in order to yield astick which was approximately 1 to 1 /2 inches in diameter andapproximately 5 inches in length and also weighed approximately 225 to230 grams.

In order to ascertain the erosion rate which would then be directlyproportional to the amount of available chlorine being generated and incommercial application would be directly proportional to the amountand/or frequency of the available chlorine being injected into a largeaqueous body such as Water in a swimming pool, the sticks were tested inan apparatus in which the sticks were mounted vertically with the upperportion of the sticks being held in place and a jet of water wasimpinged on the lower end of the stick.

The data obtained by such erosion of the stick is set forth in Table I,in addition to the data concerning the manufacture or production of thestick per se.

In order to measure the swelling characteristics of the sticks, thesticks positioned in a vertical manner were immersed in a body of waterone inch deep and at a temperature of 80 F. and allowed to stand forapproximately one hour. The extent of swelling and cracking was thendetermined by visual observation. The results of this test fordetermining the tendency of the stick to swell are also set forth nearthe bottom of Table I.

The important factors or conditions for testing a particular stick inconjunction with the erosion rates were (1) water temperature, (2) theforce and volume of water stream impinged on the stick per unit of time,(3) the stick swelling characteristics, and (4) the length of stickeroded. It was ascertained during the test that the stick should beeroded for at least 24 hours or longer to obtain reliable erosion ratesbecause shorter periods are apt to produce misleading results.

The quantitative test for ascertaining the stick erosion is set forth asfollows:

The total weight of the stick was determined prior to inserting it intothe erosion apparatus. The stick was positioned in said apparatus in avertical manner Whereby jets of water could be directed downwardlyagainst the lower end of the vertical stick. The jets of water wereapproximately & of an inch in diameter and positioned around thecircumference of the stick. The water was maintained at a temperature ofapproximately 80 F., plus or minus 1, during the erosion period. Thetotal water rate was approximately /2 gallon per 'minute. After aminimum of 24 hours the water supply was turned off and the sticks wereremoved from the erosion apparatus and re-weighed. The erosion rate andthe amount of available chlorine supplied to the erosion media weredetermined by the following formula:

(A) Weight of stick (ounces)/24 hours=w (B) Wei ht of available chlorineD (ounces)/24 hours= W where A=initial weight of the stick in ounces,B=remaining weight of the stick in ounces, C :erosion time in hours,

D=percent available chlorine in the stick.

The above formulas are generally self-explanatory. The first Formula Agives the weight of stick in ounces which was eroded during a 24-hourperiod. The second Formula B sets forth the weight in ounces ofavailable chlorine which would be provided from the erosion of the stickper 24 hours. The above data is set forth in Table I under the subtitleStick Erosion. Visual observations were also made of the swelling,crumbling and type of erosion characteristics of the stick, and theseobservations were also noted. The physical appearance of the efiluent,that is, water containing the particles of the dissolved stick was alsonoted in order to ascertain if there was any scum present on the surfacethereof. This latter data is also listed in Table I under the subtitleStick Erosion.

TABLE I.DICHLOROISOCYANURIC ACID-COPPER SULFATE- STEARATE STICKPROPERTIES Stick Number 1 z 3 Ingredients, percent:

Dichloroisocyanuric acid gran 98.5 98. 0 97. 0 Anhydrous copper sulfate,gran 0. 5 1. 0 2. 0 Sodium stearate 1. 0 1.0 0. 5 Available chlorine inthe stic 69. 0 68.6 67. 9

Water 0. 5 Stick Manufacture:

Pressure used, p.s.i 12, 000 12, 000 12, 000 Stick iormation Good GoodGood Mold release G 00d Good Good Compacting Good Good G ood Busting ofdies None None None Capping (matl sticking to die). Some Trace NoneStick length 4. 4. 75 4. 75 Stick strength G 00d Good Good StickErosion:

Ounces of stick eroded/day 4. 75 4. 32 4. 75 3. O7 2. 96 3. 23 None NoneNone None None None Irregular Irregular Irregular Scum in effluent NoneNone None Accelerated Swelling Test:

Stick swelling None None None Stick cracking None None Non 13 EXAMPLE IIDry mixed compositions containing the ingredients set forth in Table II,i.e. [(monotrichloro)te-tra-(monopotassium dichloro)]pentaisocyanura-te,anhydrous copper nitrate, and calcium stearate, were prepared in asimilar manner as set forth in Example I. After the compositions wereprepared by mixing the various ingredients together, said compositionswere compressed by a Carver press in a similar manner and under the sameconditions as set forth in Example I. The sticks produced by thecompression of a predetermined amount of said composition were thentested as described in Example I in order to ascertain the dataconcerning the erosion of such sticks.

The particle sizes of [(monotrichloro)tetra-(monopotassiumdichloro)]pentaisocyanurate and anhydrous copper nitrate were similar,i.e. granular, to the typical particle sizes of the dichlorocyanuricacid and copper sulfate utilized in preparing the compositions set forthin Example I. The particle sizes of calcium stearate were also similarto the particle size of the sodium stearate utilized in Example I, i.e.powdered material.

TABLE II. -[(MONOTRICHLORO)TETRA-(MONOPOTASSIUMDICHLORO)]PENTAISOCYANURATE-ANHYDROUS COP- PER NITRATE-CALCIUM STEARATESTICK PROPERTIES Stick Number- 4 Ingredients, percent:

[(Monotrichloro)tetra-(monopot assium dichloro)]pen taisocyanurate, gran9 Anhydrous copper nitrate, gran Calcium stearate, powder Availablechlorine in the stick 6 Stick Manufacture (2):

EXAMPLE III Additional dry mixed inorganic copper or zinc saltcompositions containing the ingredients set forth in Table III, i.e.dichloroisocyanuric acid, anhydrous copper chloride or zinc sulfate, andsodium steara-te were prepared in a similar manner as set forth inExample I. After the compositions were prepared by mixing the variousingredients together, they were compressed by a Carver press in asimilar manner and under the same conditions as set forth in Example I.The sticks produced by the compression of a predetermined amount of saidcomposition were then tested as described in Example I in order toascertain data concerning the erosion of such sticks.

Stick No. 5 contained dichloroisocyanuric acid, copper chloride, andsodium stearate and Stick No. 6 contained dichloroisocyanuric acid, zincsulfate, and sodium stearate. The particle sizes of thedichloroisocyanuric acid, copper chloride, and zinc sulfate weresimilar, i.e. granular, to the typical particle size of thedichloroisocyanuric acid and copper sulfate utilized in preparing thecompositions set forth in Example I. The particle sizes of the sodiumstearate were also similar to the particle size of the sodium stearateutilized in Example I, i.e. powdered material.

CHLORIDE O R ZINO SULFATE-SODIUM STEARATE STICK PROPERTIES Stick Number5 6 Ingredients, percent:

Dichloroisocyanuric acid, granular. 98. 0 98. 0 Copper chloride,granular anhydrous 1. 0 Zinc sulfate, granular anhydrous 1.0 Sodiumstearate, powdered 1. 0 1.0 Available chlorine in the stick 68. 6 68. 6Stick Manufacture:

Pressure used, p.s.i 11,750 11,750 Stick formation (compacting) GoodGood Mold release Good Good Rusting oi dies None None Capping Some SomeStick length, inches 4. 75 Stick strength Good Good Stick Erosion:

Ounces of stick eroded/day 5.00 4. 99 Ounces of available chlorinesupplied/ day 3. 43 3. 42 Swelling None None Crumbling None None Erosiontype 1 Scum in effluent" None None None None Stick cracking None None 1Slightly irregular.

EXAMPLE IV A dry mixed organic zinc salt composition containing theingredients set forth in Table IV, i.e. dichloroisocyanuric acid, zincacetate, and sodium stearate were prepared in a similar manner as setforth in Example I. After the compositions were prepared by mixing thevarious ingredients together, they were compressed by a Carver press ina similar manner and under the same conditions as set forth in ExampleI. The sticks produced by the compression of a predetermined amount ofsaid composition were then tested as described in Example I in order toascertain data concerning the erosion of such sticks.

The particle sizes of the dichloroisocyanuric acid and zinc acetate weresimilar, i.e. granular, to the typical particle size of thedichloroisocyanuric acid and copper sulfate, respectively, utilized inpreparing the compositions set forth in Example I. The particle sizes ofthe sodium stearate were also similar to the particle size of the sodiumsteara-te utilized in Example I, i.e. powdered material.

TATE-SODIUM STEARA'IE STICK PROPERTIES Stick Number 7 Ingredients,percent:

Dicliloroisocyanuric acid, granular 98. 0 Anhydrous zinc acetate,granular 1. 0 Sodium stearate, powdered 1.0 Available chlorine in thestick 68. 6 Stick Manufacture:

Pressure used, p.s.i 11, 750 Stick formation (compacting)- Good Moldrelease Good Busting of dies None Capping Some Stick length, inches 4.75 Stick stren th Good Stick Erosion:

Ounces of stick eroded/day 4. 88 Ounces of available chlorinesupplied/day 3. 35 Swelling None Crumblin None Erosion type Scum inPfllneni' None Accelerated Swelling Test:

Stick swellin None Stick cracking None 1 Slightly irregular.

Tables I, II, In and IV hereinbefore set forth disclose the data ofsticks utilizing various copper and zinc salts with achlorine-containing compound. Several additional sticks were preparedusing dichloroisocyanurate acid as the chlorine containing compound andwithout a copper or zinc salt combine-d therewith. These latter stickswere very unsatisfactory in that the sticks when subjected to theaccelerated swelling test exhibited severe swelling and crackingtendencies. Furthermore, additional dry mixed compositions were preparedcontaining (1) dichloroisocyanuric acid, (2) sodium stearate or calciumstearate, and (3) sodium chloride, copper acetate, sodium sulfate,calcium sulfate, or nickel chloride. These dry mixed compositions wereformulated and compressed into sticks in a similar manner as set forthin Example I. These latter sticks were found to be unsatisfactory inthat, when they were subjected to the accelerated swelling test, theyexhibited moderate to severe swelling and cracking tendencies. Thisparticular fact was quite surprising in that, for example, copperacetate which is a copper salt would normally have been expected toyield sticks capable of performing the particular desired end result,i.e. prevention of swelling and cracking of said sticks when contactedwith an aqueous media on the basis of the results obtained using coppersulfate. However, such was not the case and illustrates the criticalityof the solubility of the operable copper salts. Furthermore, it shouldbe noted that while, for example, zinc aluminate or zinc carbonate donot have the requisite solubiliities for the present inventioncomposition, these zinc salts may still function as an al-gicide and/ orfungicide but do not yield the desired end result of .preventingnon-swelling and non-cracking in a unit dosage form or stick.

In the utilization of calcium or sodium stearate in the formulations ofthe present invention, it was discovered that the use of calciumstearate produced scum in the efiluent; this may possibly result inwater transfer line plugging when used on a commercial basis. The use ofsodium stearate did not produce the aforementioned scum.

In conjunction with the aforementioned tables, it will be noted that thestick erosion rate (cited as ounces of stick eroded per day) of most allthe sticks tested averaged somewhere between the range of from about 4.0to about 5.0 ounces of stick eroded per 24 hours notwithstanding thefact that a variety of zinc or copper salts were utilized. For most usesa stick having an erosion rate below 5 ounces/24-hour period would bemost desirable since the end result is to supply available chlorine toan aqueous media at a continuous and controllable rate. An erosion ratesubstantially above 5 ounces per 24-hour period usually presentsdifiiculties in proper erosion control.

What is claimed is:

1. A sterilizing, sanitizing, and disinfecting composition, in solidshaped dosage unit form, comprising a mixture of (l) a non-deliquescent,solid, chlorine containing compound selected from the group consistingof dichloroisocyanuric acid, [=(monotrichloro)tetra-(monopotassiumdichloro)Jpentaisocyanurate, and (trichloro) (monopoitassiumdichloro)diisocyanurate, (2) from about .25 to 12.0% by weight, based onthe weight of the composition, of a metal salt of an aliphaticcarboxylic acid having at least carbon atoms in the aliphatic group,said metal being selected from the group consisting of alkali metals,alkaline-earth metals, zinc, and magnesium and (3) an anhydrous metallicsalt selected from the group consisting of anhydrous copper and zincinorganic salts, and anhydrous copper and zinc organic salts, saidcopper and zinc salts being characterized by 'having a solubility of atleast 10 grams per 100 milliliters of water at water temperature of 20C.

2. A sterilizing, sanitizing, and disinfecting composition, in $0. m s pdosage unit form, comprising an intimate mixture of granulardichloroisocyanuric acid; an anhydrous, granular copper salt of aninorganic acid; and from about 0.5% to 1.5% by weight, based on theweight of the composition, of an alkali metal stearate, with the provisothat said copper salt has a solubility of at least 10 grams per 100milliliters of water at a temperature of 20 C.

3. The composition as set forth in claim 2 wherein the copper salt iscopper chloride which comprises from about 0.25% to about 5% by weightof the total weight of said composition.

4. The composition as set forth in claim 2 wherein the copper salt iscopper sulfate which comprises from about 0.25% to about 5% by weight ofthe total weight of said comoposition.

5. The composition as set forth in claim 2 wherein the copper salt iscopper nitrate which comprises from about 0.25% to about 5% by weight ofthe total weight of said composition.

6. A sterilizing, sanitizing, and disinfecting composition, in solidshaped dosage unit form, comprising an intimate mixture of granulardichloroisocyanuric acid; an anhydrous, granular zinc salt of aninorganic acid; and from about 0.5 to 1.5% by weight, based on theweight of the composition, of an alkali metal stearate, with the provisothat said zinc salt has a solubility of at least 10 grams per 100milliliters of water at a Water temperature of 20 C.

7. The composition as set forth in claim 6 wherein the zinc salt is zincchloride which comprises from about 0.25% to about 5% by weight of thetotal weight of said composition.

8. The composition as set forth in claim 6 wherein the zinc salt is zincsulfate which comprises from about 0.25% to about 5% by weight of thetotal weight of said composition.

9. The composition as set forth in claim 6 wherein the salt is zincfluosilicate which comprises from about 0.25% to about 5% by weight ofthe total weight of said composition.

10. A sterilizing, sanitizing and disinfecting composition, in the formof a solid shaped stick, comprising a uniform mixture of (1) at least byweight dichloroisocyanuric acid, (2) from about .25% to about 2.0% byweight, based on the weight of the composition, of a metal salt of analiphatic carboxylic acid having at least 10 carbon atoms 'in thealiphatic group, said metal being selected from the group consisting ofalkali metals, alka- 1ine-earth metals, zinc, and magnesium; and (3)from about .25% to about 5% by weight anhydrous copper lactate, saidstick having a diameter of about A to 1% inches, a length of about 4 to6 inches, a Weight of about 200 to 250 grams and a density of about 90to 110 pounds per cubic foot.

11. A sterilizing, sanitizing, and disinfecting composition in the formof a solid shaped stick, comprising a uniform mixture of (1) from aboutto about 98% by weight dichloroisocyanuric acid; (2) from about 0.5% toabout 2.0% by weight anhydrous zinc acetate; and (3) from about 0.5% toabout 1.5% by weight, based on the weight of the composition of sodiumstearate, said stick having a diameter of about to 1% inches, a lengthof about 4 to 6 inches, a weight of about 200' to 250 grams and adensity of about 90 to pounds per cubic foot.

12. A process for preparing a composition for controllably releasingavailable chlorine which comprises intimately mixing (1) particles of anon-deliquescent, solid, chlorine containing compound selected from thegroup consisting of dichloroisocyanuric acid, [(monotrichloro)tetra-(monopotassium dichloro)]pentaisocyanurate, and(trichloro)(monopotassium dichloro)diisocyanurate, and having a particlesize in which substantially all of the particles pass through a No. 10mesh U.S. Standard screen and substantially all of said particles areretained on a No. 100 mesh US. Standard screen with (2) from about .25to about 2.0% by weight, based on the weight of the composition, of ametal salt of an aliphatic carboxylic acid having at least carbon atomsin the aliphatic group, said metal being selected from the groupconsisting of alkali metals, alkaline-earth metals, zinc, and magnesium,and (3) an anhydrous metallic salt selected from the group consisting ofanhydrous copper and zinc inorganic salts, and anhydrous copper and zincorganic salts, said salt being characterized by having a solubility ofat least 10 grams per 100 milliliters of water at a temperature of C.,and wherein the range of particle sizes of said anhydrous copper andzinc salts is substantially the same as the compound defined under (1),and thereafter converting, under compression at a pressure of from about3,000 to about 18,000 pounds per square inch, the resulting mixture intodosage unit form.

13. A process for preparing a composition for controllably releasingavailable chlorine into an aqueous media which comprises intimatelymixing (1) at least 90% by weight granular dichloroisocyanuric acid with(2) from about 0.25% to about 5.0% by weight of an anhydrous granularcopper salt of an inorganic acid, said anhydrous copper salt beingcharacterized by having a solubility of at least 10 grams per 100milliliters of water at a water temperature of 20 C., and (3) from about0.5% to about 1.5% by weight, based on the weight of the composition, ofsodium stearate, said stearate having a particle size of from about 1 toabout 100 microns, and thereafter compressing said mixture at a pressureof between about 3,000 and 18,000 pounds per square inch to form a stickconfiguration.

14. The process of claim 13 wherein the copper salt is copper sulfate.

15. A process for preparing a composition for controlla-bly releasingavailable chlorine into swimming pool water which comprises intimatelymixing (1) at least by weight granular dichloroisocyanuric acid with'(2) from about 0.5 to about 2.0% by weight of an anhydrous, granularzinc salt of an inorganic acid, said anhydrous zinc salt beingcharacterized by having a solubility of at least 10 grams per millitersof water at a water temperature of 20 C., and (3) from about 0.5 toabout 1.5 by weight, based on the Weight of the composition, of sodiumstearate, said stearate having a particle size of from about 1 to about100 microns, and thereafter compressing the resulting mixture under apressure of from about 3,000 to about 18,000 pounds per square inch,into a stick configuration.

16. The process of claim 15 wherein the zinc salt is zinc chloride.

References Cited by the Examiner UNITED STATES PATENTS 2,607,738 8/ 1952Hardy .16733 2,657,179 10/1953 Robinson 16713 2,913,460 11/1959 Brown260248 3,002,931 10/1961 Symes 25299 3,130,124 10/1961 Ferris 167-133,150,132 9/1964 Symes 260-248 FOREIGN PATENTS 607,971 11/ 1960 Canada.

OTHER REFERENCES Merck Index, Merck & Co., Inc., Rahway, New Jersey(1960), p. 1114.

JULIAN S. LEVITT, Primary Examiner.

S. I. FRIEDMAN, Assistant Examiner.

1. A STERILIZING SANITIZING, AND DISINFECTING COMPOSITION, IN SOLIDSHAPED DOSAGE UNIT FORM, COMPRISING A MIXTURE OF (1) A NON-DELIQUESCENT,SOLID CHLORINE CONTAINING COMPOUND SELECTED FROM THE GROUP CONSISTING OFDICHLOROISOCYANURIC ACID ((MONOTRICHLORO)TETRA-(MONOPOTASSIUMDICHLORO))PENTAISOCYANURATE, AND (TRICHLORO) (MONOPOTASSIUMDICHLORO)DIISOCYANURATE, (2) FROM ABOUT .25% TO 2.0% BY WEIGHT, BASED ONTHE WEIGHT OF THE COMPOSITION, OF A METAL SALT OF AN ALIPHATICCARBOXYLIC ACID HAVING AT LEAST 10 CARBON ATOMS IN THE ALIPHATIC GROUP,SAID METAL BEING SELECTED FROM THE GROUP CONSISTING OF ALKALI METALS,ALKALINE-EARTH METALS, ZINC, AND MAGNESIUM AND (3) AN ANHYDROUS METALLICSALT SELECTED FROM THE GROUP CONSISTING OF ANHYDROUS COPPER AND ZINCINORGANIC SALTS, AND ANHYDROUS COPPER AND ZINC ORGANIC SALTS, SAIDCOPPER AND ZINC SALTS BEING CHARACTERIZED BY HAVING A SOLUBILITY OF ATLEAST 10 GRAMS PER 100 MILLILITERS OF WATER AT WATER TEMPERATURE OF20*C.